Nut harvesters and pick up machines that are presently on the market use a conveyor belt screen that allows the debris to fall through the screen as it travels and is delivered into a cart for delivery to the processing plant. Although this approach has been used for quite some time, it does not remove all of the dirt, dust or debris. Furthermore, it does not remove sticks, a large number of which often accompany harvested tree crop product of various types.
As will be seen below, the present invention utilizes a plurality of screening and transport rollers to separate dirt and other debris from harvested nuts and other types of tree crop product. While rollers and the like have been employed in connection with harvesting of various crops for one purpose or another, the rollers or rotors differ in structure from those of the present invention. Furthermore, there is no teaching or suggestion whatsoever in the located prior art of using such systems other than in connection with harvesting of ground crops. The following patents are believed to be representative of the current state of the prior art pertaining to harvesting of ground crops: U.S. Pat. No. 7,682,235, issued Mar. 23, 2010, U.S. Pat. No. 5,980,382, issued Nov. 9, 1999, U.S. Pat. No. 5,138,826, issued Aug. 18, 1992, U.S. Pat. No. 4,696,151, issued Sep. 29, 1987, U.S. Pat. No. 4,542,687, issued Sep. 24, 1985, U.S. Pat. No. 4,136,507, issued Jan. 30, 1979, U.S. Pat. No. 4,000,747, issued Jan. 4, 1977, Chinese Patent No. CN2597104Y, issued Jan. 7, 2004, Chinese Patent No. CN201267106Y, issued Jul. 8, 2009 and Chinese Patent No. CN201153406Y issued Nov. 26, 2008 and Chinese Patent No. CN201153405Y, issued Nov. 26, 2008.